Pitch control mechanism for loader scoops



April 20, 1954 e. 'r. BAKER 2,675,933

PITCH CONTROL MECHANISM FOR LOADER SCOOPS 2 Sheets-Sheet 1 Filed Dec. 11, 1950 WK SZM April 0, 1954 G. "r. BAKER 2,675,933

PITCH CONTROL MECHANISM FOR LOADER SCOOPS Filed Dec. 11, 1950 2 Sheets-Sheet 2 r] 1 1 5 5a 59 i 59 5 .63 gl; ii 4s:a 69 i g i i V .56 49 5? 5E 52 6/ l 5/ 21.? 5;: 4 '5' 75 5 O 46 66 :1 47 ii 29 6/ ii INVENTOR. GEPflLD f 64mg A ORA/EX Patented Apr. 20, 1954 PITCH CONTROL MECHANISM FOR LOADER sooors Gerald '1. Baker, Fort Dodge, Iowa, assignor, by mesne assignments, to Avco Manufacturing Corporation, Cincinnati, Ohio, a corporation of Delaware Application December 11, 1950, Serial No. 200,293

3 Claims.

This invention relates generally to loaders of tractor mounted type and in particular to an attachment for adjusting the pitch of a pivoted load carrying unit independently of anymovement of the lift frame on which the load carrying load is supported.

In loaders of tractor mounted type the scoop or load carrying unit is usually pivotally supported between a pair of lift arms or booms for movement between a load carrying position and a load dumping position. The scoop is releasably locked in its carrying position and is free to pivotally swing at any other moved position therefor. Further, the pitch of the scoop at a carrying position is predetermined so as to be generally incapable of adjustment while the loader is in operation.

It is an object of this invention, therefore, to provide an improved loader attachment for a tractor.

Another object of this invention is to provide a pivoted scoop for a tractor loader capable of being pivotally adjusted and held in an adjusted position, at any position between the extreme moved positions therefor, independently of any movement of the lift arms.

A further object of this invention is to provide a control attachment for the material handling unit of a loader for varying the pitch of such unit at any time, in a material handling operation, to suit the particular working conditions encountered. I

Still another object of this invention is to pro-' vide a pitch control device for a material handling unit pivotally carried on a portable lift frame, adapted to move such unit to a position for handling material at a level below the ground.

support for the portable frame, and capable of rocking such unit between extreme moved posi following description when taken in connection with the accompanying drawings in which:

Fig. l is a side elevational view of a tractor loader embodying the scoop or pitch control device of this invention, with certain parts of. the tractor being broken away to more clearly show the'assembly of the loader therewith, and with the loader being illustrated in a raised position and the scoop in a load carrying position. a

Fig. 2 is illustrated similarly to Fig. 1 and showsthe scoop in an adjusted position for mov-' ing material or dirt at a level below the ground Supporting surface of the tractor;

Fig. 3 is a rear perspective view of the scoop or pitch control device of this invention, shown in position for dumping the scoop;

Figs. 4 and 5 are enlarged sectional detail views taken along the lines 4-4 and 5--5, respectively. in Fig. 3; and

Fig. 6 is an enlarged fragmentary perspective detail view showing the assembly relation of the scoop or pitch control device with the loader lift frame.

With reference to Figs. 1 and 2 of the drawings the scoop pitch control device of this invention, designated generally as 10, is shown in assembly relation with a farm tractor loader having a lifting frame including a pair of lift arms or booms ll, arranged at opposite sides of the tractor [2. Each boom II has its rear end pivoted at l3 on the tractor rear axle I4 to provide for an up and down pivotal movement of the boom, the front end l6 Of which projects for wardly of the tractor l2. Lift levers l1 corresponding to the lift arms H are arranged longitudinally of the tractor I2 with their front ends pivoted at [8 to a corresponding boom H, and with their rear ends pivoted at [9 tothe upper end of an upright guide lever 21, the lower end of which is pivoted at 22 on the tractor rear axle [4. An upright hydraulic cylinder assembly 23 corresponding to each lift arm H has the upper end thereof pivotally connected at 24 to the upright guide lever 2|, and its lower or opposite end 26 pivoted at 21 to the frame of the tractor l2.

The cylinder assemblies 23are ofsingle acting type and each has a fluid supply line 30 suitably connected with a tractor operated pump unit indicated at 28 and equipped with a suitable valve control mechanism (notshown). On the admission of oil under pressure to the cylinder assemblies 23, therefore, the lift arms II are moved to elevated positions, and on the release of such oil pressure the lift arms H are movable downwardly in response to the action of gravity,

might be termed a double U-shape having a flat. base section 33 integrally formed with three;

spaced upright leg sections 34, 36 and 31. The

bracket 32 is extended longitudinally of a trans-i verse brace member 38 connected between the front ends 1 6 or the lift arms I I at a position adjacent to and rearwardly of the scoop 29. Additional brace members 39 are welded to the transverse member 38 and to the lift arms Laterally spaced upright lugs 4| on the transverse member 38 receive therebetween a tubular sleeve member 42, which is secured to the under side of the bracket base section 33. A pin 43 inserted through the lugs 4| and sleeve 42 secures the bracket 32 to the transverse member 38, which with the lift arms constitutes the pivoted lift frame for the loader.

The scoop 29 (Figs. 3 and i) has secured to the back side of its rear wall 44 at a position adjacent to the upper end of the back wall, a mounting plate 45 of a U-shape having a flat base section 45, and vertically extended legs 47. A pivoted link structure, indicated generally at 48, of a substantially bell-crank shape, is comprised of transversely spaced upright pair of arms 49 and 49a, and 5i and 5|a, with each pair of arms 49 and 49a and 5| and 5-|a having their lower ends in a straddling relation with a corresponding leg 41 on the mounting plate 45. Pivot pins 52 extended through the lower ends of the upright arms and a corresponding leg 41 pivotally connect the link structure 48 for pivotal movement longitudinally, or in a direction fore and aft, of the tractor l2.

The upper ends of the upright arms 49 and 49a, and 5| and 5|a- (Figs. 3 and 5), are secured as by welding to'a combination spacer and cone necting bar 53. Projectedrearwa-rdly from the spacer bar 53, at positions between each pair of upright arms 49 and 49a and 5| and 5|a are a pair of arm members 54, the front ends of which are secured to the spacer bar 53 as by Welding.

Flat brace members 56 are secured, by welding, between each rearwardly extended arm '54 and the outer ones 49 and 5| of each pair of upright arms 49 and 49a and 5| and 5|a,,so that such outer upright arms, and a corresponding rear wardly extended arm 54 and brace member 55, are assembled in a substantially common plane.

It is seen, therefore, that link 48 is comprised of the upright arms 49, 49a, 5| and 51a, the. spacer bar 53, the rearwardly extended arms 54. and the brace members 56, and with the arms .54

being rigidly positioned in, planes substantiallynormal or perpendicular to the planes of the upright arms. As a result,.the complete link structure 49 is pivotally movable about the pivotpirrs '52, the link being triangular in shape and defining an apex at spacer bar 53..

Pivotally connected at 58 to the rear end 59 of each rear arm 54 are pairs of links 6|, the upper ends of which are arranged in a straddling relation with such rear' ends 59, and the lower ends of which are arranged in a straddling relationship with the outer leg sections 34 and 31 of the mounting bracket 32. These lower ends 92 are pivotally connected to the leg sections 34 and 31 by pivot pins 63. Links '61- and 48 form an articulated linkage. pivotally interconnecting scoop 29 and the lifting frame- An upright double acting hydraulic cylinder assembly 64, including a cylinder 59 and an associated piston rod 98, is arranged between the pair of links SI and the rear arm.members 54. The cylinder 9 6-, has its lower end pivotally supported at 51 on the intermediate leg 36 ofthe mounting bracket 32. The piston rod .68 has its outer end pivotally connected at 69 to the spacer bar 53. Oil lines 59 and connect the cylinder with the tractor pump unit 28.

The pairs of links 6|- are transversely spaced a distance apart corresponding to the transverse spacing of the rear arm members 54, and with this spacing corresponding in turn to the distance between the outer legs 34 and 3'! of the mounting bracket 92, so that a rear arm 54, and its corresponding upright arms, and links, are in substantially a common vertical plane extended longitudinally of the tractor.

For the purpose of guiding the pivotal movement of the links 5| and the bell crank structure 48 in substantially vertical planes, against any lateral tipping movement, there are provided a pair of combination guide and stop members 13 (Figs. .3 and i). The guide members are of a fiat bar construction arranged longitudinally of the tractor in upright planes and are formed at the front end sections with elongated slots Hi. The rear ends 16 of members it are received between a corresponding pair of links 9| and are pivotally connected to such pair of links, intermediate the ends of the links, by pivot pins ll. The front ends of members 13 are positioned between a corresponding pair of upright arms 49 and 49a, and 5| and 5m, and are movably connected with the upright arms in a lost motion connection by means of a pin 73 extended through each pair of upright arms 49 and and 5| and 5m, and through a corresponding elongated slot M in :a member is. The pins 19 are located intermediate the ends of the upright arms.

As best appears in Figs. 3 and 5 the sides of the members l3 are in bearing or contact engagement with the inner adjacent sides of their corresponding upright arms 49, 49c, and ti, 5m, and pairs of links 9|. It is to be further noted that the outer sides of members 13 are in contact or bearing engagement with the inner sides of the flat grace members 55. As a result of these multiple bearing engagements of the combination members 13 with the upright arms and links, the bell crank structure 48 and links 5| are guid-ably engaged for pivotal movementin vertical planes.

In the operation of the pitch control device l9 of this invention, assume the scoop 29 to be in its normal load carrying position as illustrated in dotted lines in Fig. 1. This position is defined by the engagement of the pins it in the upright arms 49, 49a, and 5| and 5m, with the lower or rear ends 8| of the elongated slots it formed in the members 1'9, and represents a contracted or closed position of the hydraulic assembly 54.

As the scoop 29 is elevated from its dotted line position shown in Fig. l, to a raised position illustrated in full lines in the same figure, an excessive inclination of the scoop 29 which might re suit in the dropping of material therefrom, can be eliminated during the lifting operation, by operating the pitch control device to pivot or tilt the scoop 29 in a forward and downward direction, with such an adjusted or moved position of the scoop being illustrated in Fig. l for the raised position of the scoop 29. At this position, the cylinder assembly 54 is partially extended so that the pins 18 are moved forwardly away from the rear ends iii of the slots 14, and with this po sition being maintained by the action of the hydraulic assembly 94.

To dump the scoop 29 the piston rod 69 is actuated to its fully extended position, shown in Fig. 3, and with this dumping position being defined by the engagement of th pins '18 with the upper or forward ends of the elongated slots H. In the event any material being handled adheres to the scoop 29 it is only necessary to successively extend and retract the piston rod 68 in a manner to forcibly engage the pins 18 with the slot ends 85. This successive actuation effects a positive shakin action on the scoop 29. 011 completion of a dumping operation the scoop 29 is returned to its load carrying position by merely retracting the piston rod 68 within the cylinder 66.

In some instances of loader operation it is desired that the leading or forward end 81 of the scoop 29 be inclined downwardly and forwardly to scrape or dig into a ground surface, indicated at 88, in Fig. 2, at a level below the level of the ground surface for the tractor I2. Such conditions arise where dirt to be handled has a sod covering, or where a clean scraping or removal of material, such as manure, is to be made from a relatively hard ground or concrete surface. In such instances, the pitch control device In is actuated to tilt or pivot the scoop 29 forwardly and downwardly, as illustrated in Fig. 2, so that the leading end 81 of the scoop 29 is capable of digging into the ground surface 88. Where the ground surface 88 is of a hard material, it is apparent that the leading end 81 will merely scrape or ride along such hard surface so as to gather any loose material therefrom into the scoop 29.

From the above description it is seen that there is provided a pitch control device for the scoop of a loader, which is capable of adjusting the pitch of the scoop 29 to any desired angle or position between its extreme position of movement, while the loader is in operation, and for any moved position of the loader lift arms. The device is quickly responsive to any operating condition encountered and further functions as an effective means for shaking any loose material from the scoop, after it has been dumped.

Although the invention has been described and illustrated with particular reference to the scoop of a loading machine, it i readily apparent that it is also applicable to other material handling units, now in common use on tractor loaders, such as bulldozers and scraper blades. Further, although the invention has been described and illustrated with respect to a preferred embodiment thereof it is to be understood that it is not to be so limited since changes can be made therein which are within the full intended scope of this invention as defined by the appended claims.

I claim:

1. In a tractor mounted loader including a lift frame having one end thereof pivoted on the tractor and the other end thereof projecting outwardly from the tractor, a load carrying unit pivotally supported at the projecting end of the frame, means for pivotally moving and holding the unit in a position of adjustment including a triangular link having an upright arm pivotally connected at its lower end to the unit remote from its pivotal support by the frame, and a second arm extended perpendicularly from the upper portion of said first upright arm, an upright pivoted link having the lower end thereof con- 6 nected to the frame and the upper end thereof connected to the extended end of said second arm, a hydraulic cylinder and piston assembly pivotally connected to the frame for swinging movements about an axis common to said link connection with the frame, the other end of the cylinder assembly being pivotally connected to said triangular link at the junction of said arms.

2. In a tractor mounted loader including a pivoted lift frame extending longitudinally of the tractor and having a load carrying unit pivotally supported at the forward end thereof, means for adjustably moving the unit to a plurality of positions of adjustment independently of the position of the lift frame, said means comprising a pivotal attachment on the unit remote from its pivotal support by the frame, a pair of transversely spaced upright arms connected at their lower ends to said pivotal attachment on the unit for pivotal movement about a common transverse axis, rearwardly extending arms intimately attached to the upper ends of said upright arms, a pivotal attachment on the frame remote from the pivotal support of the unit, a pair of upright link pivotally connected at their lower ends to said pivotal attachment on the frame, means for pivotally interconnecting the upper ends of said upright links to the rearwardly extended ends of said second named arms, means for guiding said upright links and arms for pivotal movement in substantially vertical planes, and a hydraulic cylinder and piston assembly swingably interconnected between the junction of said arms and said pivotal attachment on the frame.

3. In combination with a tractor mounted loader including a vertically adjustable longitudinally extending lift frame pivotally secured to the tractor and including a projectin end pivotally supporting a load carrying unit, a mechanism for imparting pivotal movement to the load carrying unit comprising a pair of articulated links pivotally connected to the load carrying unit and to the frame, the pivotal connections of said pair of articulated links both being remote fro-m the pivotal support of the unit, the link connected to the load carrying unit having divergent angularly disposed portions, and extensible means connected between the frame and said angular link at the junction of its divergent portions, said extensible means being secured to the frame adjacent the connection with said articulated linkage.

References Cited in the file of this patent UNITED STATES PATENTS McNamara, Jr July 15, 1952 

